Linux Archive

Many applications cache DNS entries to speed up DNS lookups in the event you request resources from the same server. Sometimes you need to flush this DNS cache if you know for a fact that a DNS entry has changed. How do you do that?
Flushing DNS On Windows
H:\>ipconfig /flushdns
Windows IP...

To mount a Windows file share on Linux, first create the file share on Windows and give the appropriate permissions to the user. Then, on Linux you want to do the following:
Create a directory for the mount point
mkdir -p /mnt/windows/backups
Use the mount command to mount the Windows share:
mount -t cifs //yourwindowsserver/backups...

Sometimes on Linux, you want to automatically login to a machine using ssh without being prompted for a password. How do you set this up?
First you need to generate a public/private key pair on the server you will be connecting from, lets call it
SERVERFROM
ssh-keygen -t rsa
You could also use -t...

Sometimes you need to disable the firewall in Linux from the command line. A good example is when you create a Xen virtual machine & configure VNC access. By default, the VM will boot up in init level 3 which is text mode and doesn't have a graphical desktop. After...

Many times it is convenient to mount an .iso file without burning it to a CD or DVD. Here's an example of how to mount an .iso file in Linux:
mkdir /mnt/redhat_disk2
mount -o loop -t iso9660 rhel-server-5.3-x86_64-disk2.iso /mnt/redhat_disk2...

Validating An MD5 Hash
MD5 (message digest algorithm 5) is a cryptographic hash that generates a 128-bit digital signature of a message. The message could be text or a file. The md5 message is a unique id and in theory, no two files could ever have the same md5 hash. ...